“We print 135gr/sqm on a Berberich Allegro. Can you make us a proof on this paper? Can you proof on our final publication paper?”

Our telephone support often asks for a proof on publication paper. Unfortunately, we always have to answer the question negatively. I would like to briefly explain the reasons for this in the following article.

Proofing on publication paper is still technically impossible.

All proofing systems currently certified by Fogra are based on an inkjet printer as a test printer, mostly from Epson, Canon or HP. These printers are characterised by a large colour space, good resolution and excellent homogeneity and colour stability – all characteristics that are absolutely necessary for a proof printing system. The Epson systems used by the majority of proof printers are based on 11-colour pigment inks, which can reproduce a significantly larger colour space than e.g. ISOCoatedV2. However, the prerequisite for this is the use of special papers optimized for inkjet printing, in which the pigments and inks are optimally emphasized. This requires special coatings that are optimized for optimum reproduction, fast drying, good abrasion resistance and high UV stability of the print. On an image printing paper without these coatings, the ink would run, hardly dry and would not be smudge-proof. The color space would also be impossible to achieve. A proof would therefore not be possible from this point of view.

Stamp once on a coated printing paper. You can easily wipe off the stamping ink even after many days. The situation is similar with inkjet inks. And even colour laser printers are no solution. The toner applied to the paper in these systems and then liquefied by heat to bond with the paper cannot penetrate the closed coated surfaces. This means that the print is not fused and the toner can be wiped off the surface directly after printing.

Modern digital printing systems such as the iGen from Xerox are also capable of neatly mapping color spaces such as ISOCoatedV2. Some of these systems are also able to print offset papers properly, although here too special papers optimized for digital printing are used. However, despite major improvements in recent years, these digital printing systems are still not capable of reproducing the small color deviations required for a true color-accurate proof, a “contract proof in accordance with ISO 12647-7”. Even after a complete recalibration and re-profiling on the paper used, these systems only achieve “Validation Print” quality according to ISO 12647-8.

“Validation Prints” are not “contract proofs”, they are not color-binding and not legally binding, since the permissible color deviations of Validation Prints may be significantly higher than those of real proofs. The result would therefore only be a “print”, which is not binding for a print shop as a result, not “color-binding” but only “colored goods”. And it is precisely this commitment that must be achieved with a proof. In addition, the color stability of these systems is predominantly so critical that even with a new profiling in the morning in the afternoon, even the lax validation print tolerances can no longer be achieved and the system again has to be recalibrated and profiled.

The only solution: the classic proof. If it wasn’t for the cost.

Here, real offset printing with real colours produces the real print later in an edition of one piece. Since the proof is printed in real offset printing, production paper can also be used here without any problems. The downside? The price. Depending on the format, a proof on circulation paper costs several hundred euros. Since press proofs are still predominantly film-based printed today, but the real printing is usually via computer-to-plate printing plates, there is no 100% precision of the press proof for the production print today either. CTP is also available from proofing companies, but at an even higher cost. A little postcard, a slim fanfold? This is not economically viable in proof printing.

So don’t use circulation paper for shorter print runs. Especially with ISOCoatedV2, a classic proof offers you true color accuracy and stability at very low costs. Just lay the cover paper next to it. We are sure that this is the best way for you to imagine what the subsequent printing will look like, in the “most colour-accurate” and also at the best price. And in comparison to Validation Print digital printing, it is legally binding and binding in colour.